Abstract
Plasmablastic lymphoma (PBL) is a rare, aggressive subtype of diffuse large B-cell lymphoma that has usually been associated with human immunodeficiency virus and Ebstein-Barr virus infections. Commonly seen in the oral cavity, it can affect any part of the gastrointestinal tract. This report describes a unique case of PBL that appeared in an 81-year-old immunocompetent patient. During an initial colonoscopy, a 2-cm polyp in the distal transverse colon was removed via full-thickness resection with pathology showing tubular adenoma with foci of high-grade dysplasia. After 7 months, a repeat colonoscopy found a 3-cm sessile polyp at the site of resection, which, after removal, was found to be a PBL. This is the first case described in the literature regarding the growth of PBL after full-thickness resection of a tubular adenoma in such a short interval.